Agricultural combine harvesters, called “combines” herein, travel through fields harvesting crop plants and separating their crop portions from the residue portions. The crop portions are typically saved in a container on board the combine until the vehicle is unloaded into a trailer or wagon that is located alongside the combine. The crop residue is spread across the ground to be returned to and enriching the soil.
Crop residue from combines such as cornstalks have been proposed in recent years as a source of fuel such as ethanol, or for conversion into other more useful materials such as plastic.
Collecting crop residue such as cornstalks is a problem due to their bulk and the difficulty of chopping them into sufficiently small pieces for compact transport and processing.
Traditional chopper designs are inadequate for processing cornstalks. Traditional choppers have pendulum knife blades attached to the rotor that are permitted to swing back and forth. Such knife blades extend outward from the chopper rotor by centrifugal force. This force is not sufficient to hold them in a chopping position for chopping the large masses of crop residue. New designs have been proposed that provide knife blades that are fixed rigidly to the rotor.
One of these new designs features a chopper rotor having a plurality of knife supports fixed to the rotor, each knife support having 3 blades fastened to a rear surface of a knife support. The knife blades are rigidly fixed to the rotor unlike the pendulum arrangement. In this design, disclosed in co-pending U.S. patent application Ser. No. 12/062,860, each of the 3 blades is fastened to the knife support with two threaded fasteners disposed immediately adjacent to one another, for a total of six fasteners required to attach the three blades on each knife support
Sharpening and/or replacing blades on such a chopper rotor requires the separate removal and installation of many knife blades. Each knife blade also needs to be carefully aligned, to ensure a precise gap between each pair of adjacent knife blades to accommodate a stationary blade (fixed to the chopper housing) passing therebetween. This, process is time-consuming.
What is needed, therefore, is a knife blade that reduces the time required to sharpen and/or replace. What is also needed is a knife blade that in at least one configuration reduces the total number of fasteners required to fasten the knife blades to their knife supports. What is also needed is a knife blade that in at least one configuration ensures the proper gap is provided between adjacent knife blades.
It is an object of this invention to provide such a knife blade.
In the discussion below, a “front” view of a blade or blade support on the chopper rotor is a view taken of the leading surface of the blade as the chopper rotor rotates. The “front” surface or “front” face will therefore be the leading surface or face of the blade as it is rotated on the chopper rotor, and the direction of the view is to the rear, away from the direction of travel. The “rear” view of a blade on the chopper rotor is the view taken from behind the blade or blade support on the chopper rotor as the chopper rotor rotates showing the trailing surface of the blade or blade support. Likewise the “rear” surface or “rear” face will be the trailing or rearward facing surface or face of the blade or blade support.